There is a growing number of drugs and vaccines for which the most effective, or most convenient method of administration is by delivery of a spray or mist. A variety of devices are known for delivering a controlled amount of a pharmaceutical preparation in a spray or mist to the nose, eye, ear, lungs, or throat of a user, or for topical delivery of an active agent. Various devices for delivery of a liquid or even a powdered formulation include a measured amount of a pharmaceutical composition contained in a crushable ampul, blister or other dosage form that is forced against a penetrating device during use, to pierce the dosage form to release the contents.
Although a pre-measured dosage form is a convenient way to store and then deliver a measured dose as needed, not all drugs can be stored in this manner prior to use. For example, certain active agents are unstable when combined with a liquid carrier, and certain active agents are required to be mixed just prior to administration. Many drugs, including protein drugs and vaccines may be more stable in lyophilized form and need to be hydrated just prior to use for optimal activity.
There is a need, therefore, for storage and delivery devices for measured dosages of active agent(s) in which the components of the agent(s) can be stored in a separate chamber and then mixed with a liquid or another active agent just prior to use.